The treatment and packaging of fresh pork has been a subject of intense research and development for many years. A variety of fresh pork treatment chemicals, packaging atmospheres and packaging materials are known. A vast variety of chemical treatment materials or pumping solutions have been used including sugar, salts, curing compounds, ascorbate, isoascorbate, etc. A useful atmosphere can contain varying proportions of inert gases such as argon, nitrogen, etc., red pigment forming gases such as oxygen, carbon monoxide and other gases such as carbon dioxide. Many such atmospheres have been evaluated in conjunction with a number of packaging systems. Pork packaging has been made from many types of packaging materials including paper, paperboard, corrugated paperboard, film, metallized film, foam plastic and rigid plastic wrap, etc.
We are aware of certain patents that generally teach a variety of meat packing systems. Vaughan, U.S. Pat. No. 3,047,404, teaches a packaging system for red meats. The meat is packaged in a film wrapped container which is then stored in a transportable rigid, box-like container having a high oxygen atmosphere. Voegeli et al., U.S. Pat. No. 3,154,421, discloses that a desirable bright red fresh meat color can be enhanced and maintained for about seven days if fresh meat is packaged in the ambient atmosphere. The meat is contacted with a treatment solution comprising phosphate salts, ascorbic acid or salts thereof and a sequestrant agent. Lugg et al., U.S. Pat. No. 3,851,080, teach fresh meat maintained in a controlled atmosphere containing a majority of carbon dioxide, a smaller amount of molecular oxygen, the balance being nitrogen. Preferred atmospheres contain between 10 and 40 vol % carbon dioxide, 12 and 20 vol % oxygen and 50 to 70 vol % nitrogen. Ferrar et al., U.S. Pat. No. 4,642,239, teach a package having a controlled atmosphere having a high oxygen concentration. Ferrar et al. teach a unique packaging system having a film having an oxygen permeability higher than its carbon dioxide permeability. Such a packaging system ensures that the oxygen content inside the container remains high to maintain the fresh red appearance of the meat. Cheng, U.S. Pat. Nos. 4,683,139 and 4,818,548, teaches a process for prepacking fresh meat, enhancing and improving the consistency of the meat quality at the point of retail sale and to increase the shelf life of meat. In the Cheng package, chemically treated meat is packaged in a controlled atmosphere containing 20-80% carbon dioxide and from about 2-30% oxygen, any balance is nitrogen. The treatment solution contains active components including certain phosphate compounds, a reducing agent and an organic sequestrant such as citric acid, tartaric acid, EDTA, etc. Schvester et al., U.S. Pat. No. 4,946,326, teach seafood packaging using an atmosphere having a substantial portion of inert gas such as nitrogen or argon, 50 vol % carbon dioxide and 20 vol % oxygen.
Prior art processes are costly, can be complex and often serve to merely mask spoilage and not prevent microbial growth. A substantial need exists to improve the fresh meat packaging technology relating to substantially preventing microbial growth in fresh pork products including bone-in products and bone-free products such as half carcasses, whole loins, roasts, cuts, chops, ground pork, etc. A substantial need exists to obtain tender cut pork portions, to maintain a quality of appearance and shelf stability of cut meat and to reduce purge in a simple easily used packaging system using a treatment solution and packaging. A substantial need exists to provide a product having an extended shelf life and an attractive fresh red meat appearance, while maintaining high quality flavor, stabilized microbiology, tenderness and consumer acceptance that is low in cost and easily implemented with a chemical treatment, packaging system and atmosphere.